Gas turbine engines are used to power aircraft, watercraft, power generators, and the like. Gas turbine engines typically include a compressor, a combustor, and a turbine. The compressor compresses air drawn into the engine and delivers high pressure air to the combustor. In the combustor, fuel is mixed with the high pressure air and is ignited. Products of the combustion reaction in the combustor are directed into the turbine where work is extracted to drive the compressor and, sometimes, an output shaft. Left-over products of the combustion are exhausted out of the turbine and may provide thrust in some applications.
Compressors and turbines typically include alternating stages of static vane assemblies and rotating wheel assemblies. The rotating wheel assemblies include disks carrying blades around their outer edges. When the rotating wheel assemblies turn, tips of the blades move along blade tracks included in static shrouds that are arranged around the rotating wheel assemblies. Such static shrouds may be coupled to an engine case that surrounds the compressor, the combustor, and the turbine.
The static shrouds may be exposed to high temperatures from the products of the combustion reaction in the combustor. Typical turbines are formed to include cavities arranged to receive pressurized air from the compressor which is used to cool hot turbine components such as the static shrouds. The turbines may include seals located between the turbine components to block the hot products of the combustion reaction from flowing between the turbine components into the cavities. The seals may experience large pressure forces and can degrade when a large pressure difference is formed between the hot products of the combustion reaction and the air delivered to the cavities.